U.S. Pat. No. 2,820,037 to Schmidt-Nickels describes compounds useful as intermediates for synthesizing dyes of the general formula:
where X is CN, COOH or COCl. The compound where X is COOH is referred to in later literature as “STO-609” (see below). Other related compounds useful in the dye industry are described in U.S. Pat. Nos. 4,336,383; 4,239,868; 3,960,867; 3,953,452; 2,949,467; 2,965,644; and 2,835,674.
Japanese Patent Application No. 2003-012516 by Sumitomo Pharmaceutical Co. describes compounds of the general formula:
wherein R1 and R2 are independently H, halo, alkyl, or haloalkyl, R3 is H, alkyl, or substituted alkyl, or three COOR(s) may be substituted at any location on the naphthalene ring. The compounds are said to be useful in the high throughput screening of calcium/calmodulin dependency kinase kinase (CaMKK) inhibitors, in the bioactivities in which CaMKK participates, and to offer CaMKK inhibitors useful as drugs. See also H. Tokumitsu et al., J. Biol. Chem. 277, 15813-15818 (2002), which describes STO-609 as a specific inhibitor of the Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) and as “a useful tool for evaluating the regulatory roles of caM-KK for various physiological functions” and as a tool to “distinguish between the functions of the two CaM-KK isoforms”. Id. at 15817.